Method for treating coated flexible substrates for packaging applications

Abstract

A method of treating a coated flexible substrate is described, the method of treating a coated flexible substrate includes providing a coated flexible substrate including a flexible substrate having a first surface and a second surface opposite the first surface, and at least one barrier layer on the first surface of the flexible substrate, and simultaneously providing a beam of charged particles to the at least one barrier layer of the coated flexible substrate and the flexible substrate in a substantially oxygen-free atmosphere.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure relate to methods of treating coated flexible substrates for packaging applications. [Background technology]

[0002]

[0002] Coated flexible substrates, consisting of a polymeric flexible substrate with a barrier layer deposited thereon, are known in the packaging industry for packaging food, chemicals, pharmaceuticals or agricultural products and for protecting these packaged items from harmful moisture and / or oxygen.

[0003]

[0003] The most commonly used coated flexible substrates comprise a polymeric flexible substrate on which at least one barrier layer is deposited. Currently, metals (e.g., aluminum and tinplate), polymers (e.g., EVOH or PVDC), or polymers coated with a thin metal or oxide layer are used as barrier materials in most cases. To produce such coated flexible substrates, one or more barrier layers can be deposited on the surface of the polymeric flexible substrate by an evaporation process. In some cases, a polymeric top layer is additionally provided on the barrier layer(s).

[0004]

[0004] While such commonly used barrier layers provide good protection against moisture and / or oxygen, it has been observed that their barrier properties deteriorate after a period of time. Furthermore, if the barrier layer is damaged, for example, during transportation of an article protected by the coated flexible substrate, the barrier properties of the coated flexible substrate also deteriorate. Furthermore, to protect highly sensitive articles, such as electronic devices, from moisture and / or oxygen, coated flexible substrates with very low oxygen permeability are required.

[0005]

[0005] Thus, there is a continuing need for methods to generally improve the barrier properties of coated flexible substrates for packaging applications. Summary of the Invention

[0006] In view of the above, a method for treating a coated flexible substrate for packaging applications is provided. The present disclosure aims to provide a method for improving the oxygen barrier properties of a coated flexible substrate for packaging applications. Furthermore, the present disclosure aims to enhance the oxygen barrier properties of a coated flexible substrate without requiring additional barrier materials or a complex manufacturing system. Thus, the method can be performed at low manufacturing costs and with high production efficiency. Furthermore, the present disclosure aims to provide additional protection for an article to the coated flexible substrate, which can be activated when a barrier layer disposed on the flexible substrate is damaged or when oxygen reaches the flexible substrate after diffusing through a barrier layer disposed on the flexible substrate. Additionally, the present disclosure aims to create a new function in the existing flexible substrate of the coated flexible substrate that acts as an oxygen scavenger, thereby providing additional oxygen barrier properties.

[0007]

[0007] Further aspects, advantages, and features of the present disclosure will be apparent from the claims, the specification, and the accompanying drawings.

[0008] According to an aspect of the present disclosure, there is provided a method for treating a coated flexible substrate for packaging applications. The method includes providing a coated flexible substrate including a flexible substrate having a first surface and a second surface opposite the first surface, and at least one barrier layer on the first surface of the flexible substrate. The method further includes simultaneously applying a beam of charged particles to the at least one barrier layer of the coated flexible substrate and the flexible substrate in a substantially oxygen-free atmosphere. The method further includes simultaneously applying a beam of charged particles to the at least one barrier layer of the coated flexible substrate and the flexible substrate in a substantially oxygen-free atmosphere.

[0009]

[0009] For a more particular description of the present disclosure briefly summarized above, so that the foregoing features of the present disclosure can be understood in detail, reference may be made to the following embodiments, the accompanying drawings of which relate to the embodiments and which are described below. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a flow chart illustrating a method of treating a coated flexible substrate for packaging applications according to embodiments described herein. [Figure 2] 1 shows a schematic diagram (including a microscopic view of the coated flexible substrate) to illustrate a method of processing a coated flexible substrate for packaging applications according to embodiments described herein. [Figure 3A-C] 1 shows a schematic cross-sectional view of a coated flexible substrate for packaging applications according to embodiments described herein. [Figure 4] FIG. 1 shows a schematic diagram of an apparatus for processing coated flexible substrates for packaging applications according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0011] Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in the drawings. In the following description of the drawings, like reference numerals refer to like components. Generally, only the differences with respect to individual embodiments will be described. Each example is provided by way of illustration and is not meant as a limitation of the disclosure. Furthermore, features illustrated or described as part of one embodiment can be used on or in combination with other embodiments to yield still further embodiments. It is intended that the description include such modifications and variations.

[0012] Coated flexible substrates, for example, comprise a polymeric flexible substrate and a barrier layer deposited thereon to prevent moisture and / or oxygen from diffusing or passing through the coated flexible substrate. They are known in the packaging industry for packaging food, chemicals, and pharmaceuticals, as well as technical or other agricultural products. However, it has been observed that the barrier properties of coated flexible substrates deteriorate over time. For example, if the barrier layer deposited on the flexible substrate is damaged during transportation of an item protected by the coated flexible substrate, the barrier properties of the coated flexible substrate are impaired. Furthermore, over time, oxygen may diffuse through the barrier layer disposed on the flexible substrate, thereby reducing the protection of the item against, for example, oxygen. Furthermore, to protect certain items, such as electronic devices, from oxygen, coated flexible substrates with very low oxygen permeability are required.

[0013]

[0012] The present disclosure further aims to provide a method for improving the oxygen barrier properties of a coated flexible substrate for packaging applications. Examples of packaging applications can include modified atmosphere packaging. In particular, providing a beam of charged particles to a coated flexible substrate, including at least one barrier layer and a flexible substrate, in a substantially oxygen-free atmosphere serves to create new functionality in the existing flexible substrate of the coated flexible substrate that acts as an oxygen scavenger. The newly created functionality provides the coated flexible substrate with additional oxygen barrier properties.

[0014]

[0013] Furthermore, by applying a beam of charged particles to a coated flexible substrate, including at least one barrier layer and a flexible substrate, in a substantially oxygen-free atmosphere, some polymer chains in the flexible substrate are scissioned, thereby imparting additional oxygen barrier properties to the coated flexible substrate. In other words, free radicals are generated in the flexible substrate of the coated flexible substrate as a result of applying a beam of charged particles to the coated flexible substrate and the corresponding scission of some polymer chains in the flexible substrate. The free radicals act as oxygen scavengers when oxygen reaches the flexible substrate after diffusing through the at least one barrier layer, for example, if the at least one barrier layer is damaged during transportation of the article to be protected.

[0015]

[0014] The present disclosure aims to improve the oxygen barrier properties of coated flexible substrates without the need for additional barrier materials or complex production systems, thus allowing the disclosed method to be carried out at low manufacturing costs and with high production efficiency.

[0016] 1, a method 100 for treating a coated flexible substrate for packaging applications according to the present disclosure will be described. The method 100 may begin at Start 110 and include providing a coated flexible substrate (stage 120) including a flexible substrate having a first surface and a second surface opposite the first surface, and at least one barrier layer on the first surface of the flexible substrate. Furthermore, the method 100 for treating a coated flexible substrate for packaging applications may include simultaneously applying a beam of charged particles to the at least one barrier layer of the coated flexible substrate and the flexible substrate in a substantially oxygen-free atmosphere (stage 130). The method 100 may end at End 140.

[0017] Before describing further various embodiments of the present disclosure in more detail, certain aspects will be explained in connection with certain terms used herein.

[0018]

[0017] In the present disclosure, a "flexible substrate" may be characterized by the substrate being bendable. For example, the flexible substrate may be a foil or a web. In particular, it should be understood that the embodiments described herein can be utilized to treat any type of coated flexible substrate for packaging applications. The flexible substrate described herein may comprise a substrate material selected from the group consisting of polyethylene, polypropylene, polyisobutylene, polyvinylidene chloride, polytetrafluoroethylene, polyamide, polyethylene terephthalate, polystyrene, polyethylene vinyl alcohol, polyethylene vinyl acetate, polyethylene methacrylate, and combinations thereof. The flexible substrate is particularly a polymeric flexible substrate. The flexible substrate has a substrate thickness T s But, T s ≦250μm, especially 5μm≦T s ≦150 μm, especially 5 μm ≦ T s ≦100 μm, for example, T s= 50 μm ± 1 μm. The thickness T s It is understood that by selecting a flexible substrate having the above structure, it may be advantageous to scission of some polymer chains of the flexible substrate, so that free radicals act as oxygen scavengers without deteriorating the mechanical properties of the flexible substrate.

[0019]

[0018] In the present disclosure, the term "charged particle" may be understood as a particle having an electric charge. For example, the charged particle may be an ion or an electron. According to an embodiment, the charged particle is an electron.

[0020]

[0019] In the present disclosure, the term "barrier layer" may be understood as a coating, layer, or film that provides oxygen barrier properties, particularly oxygen and moisture barrier properties, to the coated flexible substrate. The barrier layer and / or at least one barrier layer may have oxygen barrier properties, particularly oxygen and moisture barrier properties.

[0021] As an example, reference to the term "on" means, for example, that at least one barrier layer on a first surface of a flexible substrate is positioned starting from the flexible substrate, with the at least one barrier layer being positioned on the flexible substrate. In other words, the term "on" is used to define the order of at least one barrier layer, multiple barrier layers, and / or flexible substrate, where the starting point is the flexible substrate. This is regardless of whether the coated flexible substrate is depicted upside down.

[0022] 2 shows a schematic diagram (including a microscopic view of the coated flexible substrate) illustrating a method 100 for treating a coated flexible substrate for packaging applications according to embodiments described herein. The coated flexible substrate may include, inter alia, a flexible substrate 210 having a first surface and a second surface opposite the first surface, and at least one barrier layer 220 on the first surface of the flexible substrate 210. In some embodiments, the at least one barrier layer 220 may be present directly on the first surface of the flexible substrate 210.

[0023]

[0022] According to some embodiments (which can be combined with other embodiments), providing a coated flexible substrate may further include providing at least one barrier layer 220 on a first surface of the flexible substrate 210, particularly directly on the first surface of the flexible substrate 210.

[0024] In some embodiments, providing a coated flexible substrate may also include providing a coating composition on at least one barrier layer 220, for example, in a substantially oxygen-free atmosphere, particularly directly on at least one barrier layer 220. In such cases, the coated flexible substrate may further include a coating composition. Furthermore, simultaneously providing a beam of charged particles 240 to at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210 in a substantially oxygen-free atmosphere may also include simultaneously providing a beam of charged particles 240 to a coating composition in a substantially oxygen-free atmosphere. In some embodiments, the coating composition may include an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer, and combinations thereof.

[0025]

[0024] The coating composition, after being cured or polymerized, for example by applying a beam of charged particles, may form a top layer on the at least one barrier layer 220. The top layer may provide mechanical protection to the at least one barrier layer, for example against mechanical damage. The top layer may also have oxygen barrier properties, in particular moisture and oxygen barrier properties. The coating composition may be applied to the at least one barrier layer 220 using a coating method, in particular by a solution coating method, in particular by a coating method selected from the group consisting of gravure coating, flow coating, curtain coating, dip coating, spray coating, print coating, and combinations thereof. In some embodiments, the top layer may have a thickness T c is 0.1μm≦T c ≦1.5μm, especially 0.1μm≦T c ≦0.7 μm, especially 0.1 μm≦T c It can be ≦0.5 μm.

[0026] As illustrated in FIG. 2 , according to an embodiment that can be combined with other embodiments described herein, a beam of charged particles 240 can be provided from a charged particle source 230 located on the at least one barrier layer 220 or on the coating composition. Such a location of the charged particle source 230 can be advantageous because curing or polymerization of the coating composition on the at least one barrier layer 220 can be additionally performed during processing of the coated flexible substrate for packaging applications according to the present disclosure. Thus, in an embodiment having a coating composition on the at least one barrier layer 220, simultaneously providing the beam of charged particles 240 to the coating composition, the at least one barrier layer 220 of the coated flexible substrate, and the flexible substrate 210 in a substantially oxygen-free atmosphere can further include curing or polymerizing the coating composition on the at least one barrier layer 220, for example, by employing the beam of charged particles 240. The curing or polymerization of the coating composition on the at least one barrier layer 220 and the processing of the coated flexible substrate for packaging applications according to the present disclosure may be performed simultaneously.

[0027] Furthermore, the substrate thickness T of the flexible substrate 210 is determined by the position of the charged particle source 230. sThis allows the coating composition on the at least one barrier layer 220 to be cured or polymerized without passing the charged particle beam 240 through the entire surface, thereby achieving curing or polymerization of the barrier layer of the at least one barrier layer 220 with a reduced charged particle energy E. Furthermore, such a location of the charged particle source 230 can be advantageous because free radicals generated in the flexible substrate can act as oxygen scavengers only if oxygen reaches the flexible substrate after diffusing through the at least one barrier layer, or if the at least one barrier layer is damaged, for example, during transportation of goods protected by the coated flexible substrate. However, it should be understood that the location of the charged particle source 230 is not limited to a location on the at least one barrier layer 220 or on the coating composition, and any suitable location that allows curing or polymerization of the coating composition on the at least one barrier layer 220 can be used.

[0028] It should be understood that embodiments of the present disclosure are not limited to the charged particle source 230 for providing the beam of charged particles 240. The embodiments described herein are intended to illustrate the concept of a method for treating coated flexible substrates for packaging applications. Thus, it should be understood that multiple charged particle sources for providing the beam of charged particles 240 can be implemented.

[0029] In some embodiments, the beams of charged particles 240 may have a conical shape. For example, the conical shape may be substantially symmetrical about the main direction of each beam. Main direction 240M is shown in FIG. 2.

[0030] According to some embodiments (which can be combined with other embodiments), the charged particle energy E of the charged particles of the beam of charged particles 240 can be 5 keV≦E≦250 keV, in particular 30 keV≦E≦220 keV, and especially 50 keV≦E≦220 keV. In some embodiments, the charged particle dose of the beam of charged particles 240 can be between 1000 and 1×105 Gray, especially 3000~1×10 4 Gray, in particular 3000 to 8000 Gray. It should be understood that the value of the charged particle energy E of the charged particles of the beam of charged particles 240 and the value of the charged particle dose of the beam of charged particles can be adjusted according to one or more materials and / or one or more thicknesses of the at least one barrier layer and / or flexible substrate.

[0031] 2, the flexible substrate may be moved in a conveying direction T, for example, during processing of a coated flexible substrate for packaging applications according to the methods of the present disclosure. Thus, the method of processing a coated flexible substrate for packaging applications may further include moving the coated flexible substrate in a conveying direction T. For example, moving the coated flexible substrate may move the coated flexible substrate at a speed of 1 m / s≦v s ≦15m / s, especially 2m / s≦v s ≦10m / s, especially 3m / s≦v s ≦7m / s, e.g., v s = 4.5 m / s ± 0.5 m / s, or v s = 6.0 m / s ± 0.5 m / s. According to another example, the velocity v at which the coated flexible substrate is moved may be s , 12m / s≦v s It can be ≦15 m / s.

[0032] 2, a beam of charged particles 240 provided simultaneously in a substantially oxygen-free atmosphere to the at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210 can simultaneously penetrate the at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210. In embodiments having a coating composition on the at least one barrier layer 220, a beam of charged particles 240 provided simultaneously in a substantially oxygen-free atmosphere to the coating composition, the at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210 can simultaneously penetrate the coated composition, the at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210.

[0033] In some embodiments, simultaneously providing the beam of charged particles 240 to the at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210 in a substantially oxygen-free atmosphere may further include adjusting at least one of a charged particle energy E of the charged particles of the beam of charged particles 240 and a charged particle dose of the beam of charged particles 240. In embodiments having a coating composition on the at least one barrier layer 220, simultaneously providing the beam of charged particles 240 to the coating composition, the at least one barrier layer 220 of the coated flexible substrate and the flexible substrate 210 in a substantially oxygen-free atmosphere may further include adjusting at least one of a charged particle energy E of the charged particles of the beam of charged particles 240 and a charged particle dose of the beam of charged particles 240.

[0034]

[0033] Thus, varying the charged particle energy E of the charged particles of the charged particle beam 240 adjusts the average penetration depth 210p of the charged particle beam 240 into the flexible substrate 210. Thus, scission of polymer chains of the flexible substrate 210 can be performed and corresponding free radicals can be created at various penetration depths into the flexible substrate 210. Furthermore, varying the charged particle dose of the charged particle beam 240 adjusts the number of scission of polymer chains of the flexible substrate 210 and the corresponding free radicals at the average penetration depth 210p into the flexible substrate 210.

[0035] In this disclosure, the term "penetration depth" refers to the distance that the beam of charged particles 240 penetrates into the flexible substrate 210 starting from the first surface of the flexible substrate 210, e.g., at which distance, e.g., along the thickness direction, at least one barrier layer is positioned or deposited. In some embodiments, the average penetration depth 210p of the charged particles of the beam of charged particles 240 in the flexible substrate 210 from the first surface is 1 / 2 times the substrate thickness T of the flexible substrate. S At least 10% of the substrate thickness T, especially for flexible substrates S at least 40% of the substrate thickness T S is at least 70% of the

[0036] 3A-3C show schematic cross-sectional side views of coated flexible substrates for packaging applications according to embodiments described herein. In FIG. 3A-3C, the coated flexible substrate according to the present disclosure includes a flexible substrate 310 having a first surface and a second surface opposite the first surface, and at least one barrier layer 320 on the first surface of the flexible substrate 310, specifically directly on the first surface of the flexible substrate 310.

[0037]

[0036] In some embodiments, as illustrated in Figure 3A, a coated flexible substrate according to the present disclosure may include a flexible substrate 310 having a first surface and a second surface opposite the first surface, and at least one barrier layer 320 on the first surface of the flexible substrate 310, particularly directly on the first surface of the flexible substrate 310.

[0038] 3B , a coated flexible substrate according to the present disclosure may include a flexible substrate 310 having a first surface and a second surface opposite the first surface, a first barrier layer 320a on the first surface of the flexible substrate 310, particularly directly on the first surface of the flexible substrate 310, and a second barrier layer 320b on the first barrier layer 320a, particularly directly on the first barrier layer 320a. Thus, at least one barrier layer 320 may include a first barrier layer 320a and a second barrier layer 320b. As an example, the first barrier layer 320a may include aluminum or aluminum oxide. Furthermore, the second barrier layer 320b may include an organic material, such as an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer, a polyacrylate, a polymethacrylate, a melamine resin, or a combination thereof.

[0039] 3C , a coated flexible substrate according to the present disclosure may include a flexible substrate 310 having a first surface and a second surface opposite the first surface, a first barrier layer 320a on the first surface of the flexible substrate 310, particularly directly on the first surface of the flexible substrate 310, a second barrier layer 320b on the first barrier layer 320a, particularly directly on the first barrier layer 320a, and a third barrier layer 320c on the second barrier layer 320b, particularly directly on the second barrier layer 320b. Thus, at least one barrier layer 320 may include the first barrier layer 320a, the second barrier layer 320b, and the third barrier layer 320c. As an example, the first barrier layer 320a may include aluminum or aluminum oxide, and the second barrier layer 320b may include silicon dioxide. Furthermore, the third barrier layer 320c may include an organic material, such as an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer, a polyacrylate, a polymethacrylate, a melamine resin, and a combination thereof. As a further example, the first barrier layer 320a may include polyvinyl alcohol and / or polyethylene vinyl alcohol. Furthermore, the second barrier layer 320b may include aluminum, aluminum oxide, and / or silicon dioxide. Furthermore, the third barrier layer 320c may include an organic material, such as an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer, a polyacrylate, a polymethacrylate, a melamine resin, and a combination thereof.

[0040] At least one barrier layer 320, or at least one of the at least one barrier layers 320, such as the first barrier layer 320a, the second barrier layer 320b, or the third barrier layer 320c, may include a material selected from the group consisting of aluminum, aluminum oxide, aluminum nitride, silicon, silicon dioxide, an organic material, and combinations thereof. Examples of the organic material include polyvinyl alcohol, polyethylene vinyl alcohol, polyvinylidene dichloride, an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer, a polyacrylate, a polymethacrylate, a melamine resin, and combinations thereof. However, it should be understood that the material of the at least one barrier layer 320, or at least one barrier layer of the at least one barrier layer 320, is not limited to aluminum, aluminum oxide, aluminum nitride, silicon, silicon dioxide, organic materials, and combinations thereof, and that any suitable material having oxygen barrier properties, in particular moisture and oxygen barrier properties, can be used as the material of the at least one barrier layer 320, or at least one barrier layer of the at least one barrier layer 320.

[0041] In some embodiments, at least one barrier layer 320, or at least one of the at least one barrier layers 320, e.g., first barrier layer 320a, second barrier layer 320b, or third barrier layer 320c, can be an oxygen barrier. In some embodiments, at least one barrier layer 320, or at least one of the at least one barrier layers 320, e.g., first barrier layer 320a, second barrier layer 320b, or third barrier layer 320c, can be a moisture and oxygen barrier.

[0042] In some embodiments, the water vapor transmission rate (WVTR, in g / cm) of a coated flexible substrate treated according to the methods of the present disclosure is 2 / day) and / or oxygen transmission rate (OTR) may be less than 10, particularly less than 1, especially about 0.5. Oxygen and water vapor transmission rates may be determined according to ASTM D3985-17 and ASTM F1249-20 using Mocon Oxtran 2 / 22 and Systech Illinois 8001 for oxygen transmission and Mocon Permatran-W 3 / 33 and Systech Ilinois 7001 for water vapor transmission.

[0043] According to some embodiments, the at least one barrier layer 320, or at least one of the at least one barrier layers 320, such as the first barrier layer 320a, the second barrier layer 320b, or the third barrier layer 320c, can be fabricated by chemical vapor deposition or physical vapor deposition, such as sputtering or evaporation. Examples of physical vapor deposition can be electron beam physical vapor deposition and sputter deposition. In some embodiments, providing a coated flexible substrate can include depositing the at least one barrier layer on the flexible substrate, in particular directly on the flexible substrate.

[0044] Alternatively, the at least one barrier layer 320, or at least one of the at least one barrier layers 320, e.g., the first barrier layer 320a, the second barrier layer 320b, or the third barrier layer 320c, can be provided on the at least one barrier layer 310 using a coating method, in particular a solution coating method, in particular a coating method selected from the group consisting of gravure coating, flow coating, curtain coating, dip coating, spray coating, and combinations thereof (for example, when the precursor of at least one barrier layer of the at least one barrier layer 320 (e.g., the first barrier layer 320a, the second barrier layer 320b, or the third barrier layer 320c) is liquid and includes an organic material, e.g., polyvinyl alcohol, polyethylene vinyl alcohol, acrylate monomer, methacrylate monomer, acrylate oligomer, methacrylate oligomer, polyacrylate, polymethacrylate, melamine resin, and combinations thereof). In some embodiments, the thickness T of at least one barrier layer 320 b However, 0.05 μm≦T b ≦5μm, especially 0.1μm≦T b ≦2 μm, in particular 0.1 μm≦Tb≦1 μm.

[0045] According to aspects of the present disclosure, a coated flexible substrate for packaging applications is provided. In some embodiments, the coated flexible substrate may be a substrate treated by the method of the present disclosure. The coated flexible substrate may include a flexible substrate having a first surface and a second surface opposite the first surface, and at least one barrier layer on the first surface of the flexible substrate. In some embodiments, the at least one barrier layer may be directly on the first surface of the flexible substrate. The properties of the flexible substrate and the properties of the at least one barrier layer of the treated and coated flexible substrate for packaging applications, such as the substrate thickness T s , substrate material, thickness T band the material of the at least one barrier layer is as described herein. In some embodiments, the water vapor transmission rate (WVTR) of the coated flexible substrate is 0.01 g / cm. 2 / day) and / or oxygen transmission rate (OTR) may, for example, be less than 10, particularly less than 1, and especially about 0.5 after being treated according to the methods of the present disclosure. Oxygen and water vapor transmission rates can be determined as described herein.

[0046] 4, an apparatus 400 for processing a coated flexible substrate 440 for packaging applications according to the present disclosure is depicted. According to an embodiment that may be combined with other embodiments described herein, the apparatus 400 includes a processing drum 410 for guiding the coated flexible substrate 440. Additionally, the apparatus 400 includes a printing arrangement 420 for printing, e.g., a coating composition, on at least one barrier layer of the coated flexible substrate 440. By way of example, the at least one barrier layer may include aluminum or aluminum oxide. Additionally, the apparatus 400 includes a charged particle source 430 for processing the coated flexible substrate 440.

[0047] 4, the printing arrangement 420 may include a supply device 421 for supplying the coating composition. For example, the supply device 421 may be a monomer reservoir. Furthermore, the printing arrangement 420 may include a first roller 422 (e.g., an anilox roller) and a second roller 424 (e.g., a transfer roller). In particular, the first roller 422 may be arranged parallel to the processing drum 410 and the second roller 424. Between the transfer roller and the processing drum 410, the coated flexible substrate 440 may be transported during processing, for example, during coating or printing of the coating composition on at least one barrier layer of the coated flexible substrate 440. Thus, it should be understood that the coating composition may be applied from the reservoir to the surface of the first roller 422, for example, the surface of the anilox roller, while the surface of the first roller 422 passes through the reservoir. As also illustrated in FIG. 4, the printing arrangement 420 typically includes a doctor blade assembly 423 having at least one elongated doctor blade extending in a direction parallel to the axis of rotation of the first roller 422 .

[0048]

[0047] This written description uses examples to disclose the disclosure, including the best mode, and to enable any person skilled in the art to practice the described subject matter, including making and using any apparatus and performing any incorporated methods. While various specific embodiments have been disclosed as described above, mutually non-exclusive features of the above-described embodiments may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

[0049]

[0048] While the foregoing is directed to several embodiments, other and further embodiments may be devised without departing from the basic scope, which scope is determined by the claims that follow.

Claims

1. 1. A method for treating a flexible substrate for packaging applications, comprising: providing a flexible substrate having a first surface and a second surface opposite the first surface; depositing a plurality of barrier layers on the first surface of the flexible substrate; and Simultaneously applying a beam of charged particles to the plurality of barrier layers of the flexible substrate and to the flexible substrate in a substantially oxygen-free atmosphere to measure the water vapor transmission rate (WVTR, in g / cm) of the flexible substrate having the plurality of barrier layers deposited thereon. ２ / day) and / or oxygen transmission rate (OTR) to be less than 10; Including, simultaneously providing a beam of charged particles to the plurality of barrier layers of the flexible substrate and the flexible substrate in a substantially oxygen-free atmosphere includes adjusting a charged particle energy E of the charged particles of the beam of charged particles; The method, wherein the beam of charged particles penetrates from the first surface of the flexible substrate to an average penetration depth equal to at least 10% of a substrate thickness T S of the flexible substrate.

2. The method of claim 1 , wherein the beam of charged particles is provided from a charged particle source positioned above the plurality of barrier layers.

3. 3. The method of claim 1, wherein simultaneously providing a beam of charged particles to the plurality of barrier layers of the flexible substrate and the flexible substrate in a substantially oxygen-free atmosphere further comprises adjusting a charged particle dose of the beam of charged particles.

4. 4. The method according to claim 1, wherein the charged particles of the beam of charged particles have a charged particle energy E in the range 5 keV≦E≦250 keV.

5. The charged particle dose of the beam of charged particles is 1000 to 1×10 ５ 5. The method according to claim 1, wherein the color is gray.

6. The substrate thickness T of the flexible substrate Ｓ 6. The method of claim 1, wherein the thickness of the film is ≦250 μm.

7. 7. The method of any one of claims 1 to 6, wherein the flexible substrate comprises a substrate material selected from the group consisting of polyethylene, polypropylene, polyisobutylene, polyvinylidene chloride, polytetrafluoroethylene, polyamide, polyethylene terephthalate, polystyrene, polyethylene vinyl alcohol, polyethylene vinyl acetate, polyethylene methacrylate, and combinations thereof.

8. The method of claim 1 , wherein the charged particles are electrons.

9. The total thickness T of the plurality of barrier layers ｂ However, 0.05 μm≦T ｂ 9. The method of claim 1, wherein the thickness is ≦5 μm.

10. 10. The method of claim 1, wherein the plurality of barrier layers comprises a first barrier layer selected from the group consisting of aluminum, aluminum oxide, aluminum nitride, silicon, and silicon dioxide, and a second barrier layer comprising an organic material selected from the group consisting of acrylate monomers, methacrylate monomers, acrylate oligomers, methacrylate oligomers, polyacrylates, polymethacrylates, melamine resins, and combinations thereof.

11. further comprising providing a coating composition over the plurality of barrier layers; 10. The method of claim 1, wherein providing a beam of charged particles further comprises simultaneously providing a beam of charged particles to the coating composition in a substantially oxygen-free atmosphere.

12. The method of claim 11 , wherein the coating composition comprises an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer, and combinations thereof.

13. 13. The method of claim 11 or 12, wherein providing the beam of charged particles polymerizes the coating composition to form a top layer on the plurality of barrier layers.

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